JPH08207743A - Boost-type fluid brake gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide braking work regardless of a will of a driver of a vehicle in extremely simple structure. SOLUTION: This boost type fluid brake system is constituted of a master cylinder 200, an air pressure booster 300 to drive a pressure relief device 400 and a control device 100 to control the master cylinder and the booster. A solenoid valve 500 is arranged in one of conduits 36, 38 to connect chambers 18, 20 of the control device 100 to chambers 26, 28 of the booster 300.

Description

Detailed Description of the Invention

The present invention relates to a boost type hydraulic brake system of the type used in motor vehicles, comprising a pneumatic booster and a master cylinder.

Such devices conventionally include a pneumatic booster, the casing of the booster being fixed via its rear part to the wall separating the driver's cab from the vehicle's engine compartment, by means of a movable wall structure. A front chamber, which is always connected to the partial vacuum source, and a front chamber or a rear chamber, which is selectively connected to a high-pressure source via a valve device driven by the control rod, are sealed off and the control rod is It can come into contact with the rear surface of the reaction disk fixed to the push rod coaxial with the control rod through the front surface of the plunger. Since the master cylinder is usually fixed to the front part of the casing of the booster, the push rod of the booster interacts with the piston of the master cylinder when driving the control rod of the booster, and this control rod penetrates the opening of the bulkhead, Driven by the brake pedal.

However, it may not be possible to place the booster directly between the brake pedal and the master cylinder. Such a situation occurs, for example, in a vehicle in which the driving position is located to the right of the vehicle and the diametrical space requirement of the booster precludes such an arrangement in the engine compartment.

European Patent No. 0,326,965 or British Patent No. 2,200,419 provide a solution to this problem by allowing the pneumatic booster to be separated from the master cylinder. There is. In this design, the modules for controlling the booster and the master cylinder are arranged on an extension of the control rod driven by the brake pedal, allowing the booster itself to be installed anywhere in the engine compartment. The control module includes a valve that selectively communicates the first chamber with a second chamber, which is always connected to the partial vacuum source, or a high pressure source, in this case the atmosphere. The two conduits connect the control module chamber to the booster chamber, and the booster drives a single-system master cylinder connected to the control module boost chamber, so that the input exerted by the control rod is due to this boost force. It is amplified and acts on the push rod that drives the master cylinder connected to the brake motor.

However, these braking devices are very complex, especially for the functions of preventing wheel spin during acceleration and of electrically controlled automatic braking.
It is not easy to meet the demanded functions of most braking systems today.

As a result, it is an object of the present invention to provide a boost hydraulic brake system of a simple design that allows easy control of traction control or automatic braking operation independent of the driver's will. .

To this end, the present invention provides a pneumatic booster having a front partial vacuum chamber and a rear working chamber separated by a movable sealing partition secured to the drive rod, and a pressure relief device driven by the drive rod. Controlling the pneumatic booster with a valve element driven by the control rod to selectively communicate the first chamber with the second chamber or the high pressure source, the control rod including at least one brake motor. A push rod for driving a master cylinder connected to the first cylinder via a reaction disc, the first pipe communicating the first chamber of the controller with the working chamber of the booster, and the second pipe of the second cylinder of the controller. The chamber is communicated with the partial vacuum chamber of the booster, and the control device slides in the hole to move the first chamber into the hole.
A boost hydraulic brake system is provided that includes a piston defining a chamber, a second chamber and a boost chamber connected to a pressure relief device.

According to the invention, a solenoid valve is arranged in one of the lines connecting the control unit chamber to the booster chamber. Advantageously, the solenoid valve may be arranged in a first line connecting the first chamber of the control device to the working chamber of the booster, the solenoid valve preferably being of the three-way, two-position type. In this case, the solenoid valve allows communication between the first chamber of the control device and the working chamber of the booster in the first position,
In position, this communication is blocked and the working chamber of the booster is connected to a high pressure source.

In a method which is also advantageous, the solenoid valve may be arranged in a second line connecting the second chamber of the control device to the partial vacuum chamber of the booster, the solenoid valve preferably being of the three-way two-position type. belongs to. In this case, the solenoid valve allows communication between the second chamber of the control device and the partial vacuum chamber of the booster in the first position, blocks this communication in the second position, and uses the second chamber of the control device as a high pressure source. Connecting.

Other objects, features and advantages of the present invention will be apparent from the following description of embodiments, which will be given by way of example with reference to the accompanying drawings.

FIG. 1 shows, for example, a cross-section of a braking device known from the above specification, so that this braking device will be described briefly. The braking device is a control device or module, generally designated 100, a master cylinder 200, a pneumatic booster 300 and a pressure relief device 400, which in the illustrated example is a single-system master cylinder.
Consists of.

By convention, the direction in which the movable parts move when driven is referred to as "forward" and the direction in which these parts move back to the rest position is referred to as "rearward". Therefore, in the figure, the front is the left side and the rear is the right side.

The control module 100 is driven by a control rod 10 which is connected to a brake pedal (not shown) located in the vehicle cab. The control module 100 includes a body 12 having a stepped hole 14 in which a stepped piston 16 slides in a sealed manner. The piston 16 has a first portion formed inside the hole 14 behind the hole.
It is divided into a chamber 18 and a second chamber 20 which is formed in the front and is always connected to the partial vacuum source V.

The first chamber 18 is provided by a conventional three-way valve element 22 which is arranged in the housing of the piston 16 and is driven by a plunger 23 fixed to the control rod 10.
It selectively communicates with the second chamber or a high pressure source A which is, for example, the atmosphere.

The pneumatic booster 300 includes a movable sealing partition 3
It is formed by a casing 24 whose inside is divided into a front chamber 26 and a rear chamber 28 which are always connected to the partial vacuum source V by 0. The partition wall 30 is fixed to the drive rod 32, and is fixed to the front wall of the casing 24.
00 piston 34.

The rear chamber 28 of the booster 300 has an air duct 3
It is connected by 6 to the first chamber 18 of the control module 100. Similarly, the front chamber 26 of the booster 300 is connected to the second chamber 20 of the control module 100 by an air line 38. The outlet of the pressure relief device 400 is connected by a fluid line 40 to an annular drive chamber or boost chamber 42 formed in the body 12 of the control module 100 between the shoulders of the stepped hole 14 and the stepped piston 16. .

The operation of this braking device is also known.
At rest, all moving parts are in the rear position shown in FIG. In this position, the valve element 22 has the control module 1
The communication between the first chamber 18 and the high pressure source A is blocked while allowing the communication between the first chamber 18 and the second chamber 18 of No. 00. Thus, chambers 18 and 20 are at the pressure of partial vacuum source V, and the front and rear chambers 26 and 28 of booster 300, which they communicate with via lines 36 and 38, are also at the same pressure.

When the driver of the vehicle drives the brake pedal, the control rod 10 moves forward. The plunger 23 then causes movement of the valve element 22, which first isolates the chambers 18 and 20 from one another and then brings the first chamber 18 into communication with the high pressure source A. As a result, the pressure in the first chamber 18 transmitted to the rear chamber 28 of the booster 300 via the pipe 36 is increased, and the front chamber 26 of the booster is always connected to the partial vacuum source V.

This pressure difference is exerted on both sides of the movable sealing partition 30 and tries to move this partition forward, so that the drive rod 32 moves the piston 34 of the pressure release device 400 and is transmitted to the boost chamber 42. This causes an increase in the pressure in the line 40.

The pressure in the annular chamber 42 is exerted on the piston 16 to move it forward. The piston 16 includes an annular surface surrounding the front surface of the plunger 23, these two surfaces abutting a reaction disc 44 secured to a push rod 46. Therefore, the reaction disk 44 simultaneously receives the input transmitted by the plunger 23 and the boosting force transmitted by the piston 16 in which the pressure in the chamber 42 is exerted. The reaction disc 44 and push rod 46 transmit the resultant of these two forces to the piston 48 of the master cylinder 200, which in turn causes an increase in pressure in the brake motor 50, which in effect drives the vehicle. Provides the enhanced braking action required by the person.

According to the invention, it is very easy to obtain a braking action which is independent of the intention of the driver of the vehicle, for example to obtain a traction control or an automatic braking action.

In the embodiment shown in FIG. 1, the solenoid valve 5
00 is arranged in the conduit 36 connecting the first chamber 18 of the control module 100 to the rear chamber 28 of the booster 300. The solenoid valve 500 is a 3-way 2-position type. Solenoid valve 500 allows communication between the two chambers 18 and 28 in the illustrated rest position, thus allowing the brake system to operate as previously described.

The vehicle has a large number of sensors (not shown).
And a computer (not shown). When the computer detects that the rotational speed of the driving wheels is too high with respect to the rotational speed of the non-driving wheels of the vehicle, for example,
Energize solenoid valve 500. Proximity sensors can also detect the presence of obstacles and excessive relative speed due to comparison with the vehicle in front.

Solenoid valve 500 switches to its second position when energized, in which position the solenoid valve is at the 2nd position.
The two chambers 18 and 28 are isolated from each other and allow the booster rear chamber 28 to communicate with a high pressure source A or atmosphere. As a result, the pressure in the rear chamber 28, which has received the pressure of the partial vacuum source V, rises, and a pressure difference occurs between the pressure in the rear chamber 28 and the front chamber 26 of the booster through which the pressure of the partial vacuum source V flows.

This pressure difference is exerted on the two surfaces of the movable sealing partition 30, and the partition is moved forward to move the pressure release device 4.
Try to activate 00. As a result, the pressure in the annular chamber 42 rises, and this pressure is exerted on the piston 16 to generate a force for driving the master cylinder 200 and the brake motor 50 on the reaction disc 44 and the push rod 46. Therefore, in order to brake the drive wheels to prevent spins during acceleration, or to brake the vehicle when obstacles are considered to be very close, a brake controlled by an onboard computer The drive is virtually obtained.

As soon as the traction control situation or the presence of an obstruction disappears, the computer causes the solenoid valve 500 to
, And then the solenoid valve returns to the rest position shown. Therefore, the rear chamber 28 of the booster 300 is the first chamber 1 of the control module 100 through which the pressure of the partial vacuum source V flows.
8 again via line 36.

Since the first chamber 18 communicates with the partial vacuum source V, the pressure difference between the booster chambers 26 and 28 is canceled out, and the movable sealing partition 30 has a return spring 52 arranged in the front chamber 26 of the booster. It is possible to return to its rear rest position under the action of. Therefore, the piston 34 of the pressure release device 400 is returned to the rear, which causes the pressure in the line 40 and the boost chamber 42 to drop.

Then, the piston 16 also returns the push rod 46 and the piston 48 of the master cylinder 200 to the rear while the return spring 5 arranged in the hole 14 is returned.
4 to return it to its rear rest position. Therefore, the pressure in the brake motor 50 decreases, the initial value is restored, and the operation period of traction control or automatic braking ends.

Moreover, during the traction control or automatic braking, if the computer detects that the braking thus obtained is too strong, the computer returns the solenoid valve 500 to its rest position and then re-opens the solenoid valve. Energized to achieve the desired braking action or pressure in the brake motor 50 or booster rear chamber 28.
The desired pressure within can be obtained. Therefore, by changing the excitation current of the solenoid valve 500 in this way, it is possible to obtain exactly the required braking action as a function of external conditions, for example by changing the pulse width or the duty cycle. .

It can thus be seen that the function of traction control or automatic braking is obtained in a boosted hydraulic brake system in a very simple, effective and reliable manner. In fact, the solenoid valve used is of the two-position type, which makes it particularly simple, reliable and inexpensive. Furthermore, the solenoid valve constitutes the only additional element necessary to fulfill this function.

Furthermore, in the operating phase of traction control or self-braking, if the solenoid valve 500 is placed in close proximity to the rear chamber 28 and is properly dimensioned, the air flowing through this chamber will be in that position. Since there is virtually no resistance in the flow path, the pressure rise in the rear chamber 28 of the booster is very rapid.

Similarly, when the solenoid valve 500 returns to its rest position, the pressure balance in the two chambers 26 and 28 of the booster is reestablished very quickly, so that the braking system rapidly assumes its initial configuration. Then, the driver of the vehicle can take back the braking control again.

A proportional solenoid valve can be used to obtain smaller changes in braking and to avoid causing vibration and noise by rapidly moving the spool of solenoid valve 500 back and forth, ie, this valve. The position of the spool controlling the communication between the three flow paths is a function of the strength of the current flowing through the coil of the solenoid valve.

It will also be appreciated that this pressure can be controlled by solenoid valve 500 as long as the pressure in rear chamber 28 is less than atmospheric pressure. Therefore, during the braking action, when the pressure in the rear chamber 28 is between the pressure of the high pressure source A and the pressure of the partial vacuum source V, due to the sensor installed in the vehicle, the pressure in the rear chamber 28 and the braking force are reduced. It is possible to drive the solenoid valve 500 to simultaneously increase the strength of the solenoid valve.

FIG. 2 shows a modification of the above-described embodiment, in which the same components are designated by the same reference numerals.
According to this variant, it can be seen that the solenoid valve 500 ′ is arranged in the line 38 connecting the front chamber 26 of the booster 300 to the second chamber 20 of the control module 100.

Solenoid valve 500 'enables the brake system to actuate under the action of control rod 10 in the same manner as previously described for vehicle driver braking control when in the rest position shown in FIG. ing.

The solenoid valve 500 ', when energized,
On the one hand the mutual communication between the chambers 26 and 20 and on the other hand the communication between the second chamber 20 and the partial vacuum source V is blocked and the second chamber 20 is connected to the high pressure source A. The resulting increase in pressure in the second chamber 20 is transmitted to the first chamber 18 communicating with this chamber 20 in the rest state and then to the rear chamber 28 of the booster via the line 36. This results in the actuation of the vehicle brakes for traction control or automatic braking actuation, as described above with respect to FIG.

When the solenoid valve 500 'is deenergized and returned to its rest position, the second chamber 20 is reconnected to the partial vacuum source V, which is not only the pressure in this chamber but also the chamber 1.
It also has the effect of lowering the pressure in 8 and 28. As a result, as described above, the entire braking device is returned to the rest position, and the traction control or the braking related to the automatic braking phase is ended.

Also in this embodiment, the proportional solenoid valve 50
It is possible to use 0 '.

Of course, the present invention is not limited to the embodiments described above, and it will be apparent to those skilled in the art that many modifications can be accepted within the scope of the present invention.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a boost type fluid brake device configured according to the present invention.

FIG. 2 is a sectional view of a modification of the embodiment of FIG.

[Explanation of symbols]

 10 control rod 12 main body 14 stepped hole 16 stepped piston 18 first chamber 20 second chamber 22 three-way valve element 23 plunger 24 casing 26 front chamber 28 rear chamber 30 movable sealing partition wall 32 drive rod 34 piston 36, 38 air duct 40 Fluid Line 42 Annular Drive Chamber or Boost Chamber 44 Reaction Disk 46 Push Rod 48 Piston 50 Brake Motor 52, 54 Return Spring 100 Controller or Module 200 Master Cylinder 300 Pneumatic Booster 400 Pressure Release Device 500, 500 'Solenoid Valve A High Pressure source V Partial vacuum source

Claims (9)

[Claims] 1. A front partial vacuum chamber (26) separated by a movable sealing partition (30) secured to a drive rod (32).
And a pneumatic booster (300) with a rear working chamber (28), a pressure relief device (400) driven by a drive rod (32), and a first chamber (18) driven by a control rod (10). A device (10) for controlling a pneumatic booster (300) comprising a valve element (22) for selectively communicating the second chamber (20) or the high pressure source (A).
0) and the control rod (10) is at least 1
A push rod (46) for driving a master cylinder (200) connected to two brake motors (50) via a reaction disc (44), and a first pipe line (36)
Controls the booster (3) in the first chamber (18) of the control device (100).
00) to the working chamber (28), and the second conduit (38)
Controls the second chamber (20) of the control device (100) by the booster (3
00) to the partial vacuum chamber (26), and the control device (1
00) slides in the hole (14) and enters the first chamber (1
8), a second chamber (20) and a boost chamber (42) connected to the pressure relief device (400) defining a piston (1)
In a boost fluid brake system including 6), a solenoid valve (500) connects a chamber (18, 20) of a controller (100) to a chamber (26, 2) of a booster (300).
8) A boost type fluid brake device, characterized in that it is arranged in one of the pipe lines (36, 38) connected to 8). 2. The boost type fluid brake system according to claim 1, wherein the solenoid valve (500) is a controller (10).
The boost type fluid brake device is characterized in that it is arranged in a first pipe line (36) connecting the first chamber (18) of 0) to the working chamber (28) of the booster (300). 3. The boost type fluid brake system according to claim 2, wherein the solenoid valve (500) is of a proportional type. 4. The boost type fluid brake system according to claim 2, wherein the solenoid valve (500) is a three-way two-position type. 5. The boost type fluid brake system according to claim 3 or 4, wherein when the solenoid valve (500) is in the first position, the first chamber (18) of the control device (100) and the working chamber of the booster (300) ( 28) allowing communication with the booster (300) and blocking this communication in the second position.
A boost type fluid brake device, characterized in that the working chamber (28) of the above is connected to a high pressure source (A). 6. The boost type fluid brake system according to claim 1, wherein the solenoid valve (500 ') is a controller (1).
00) is arranged in a second pipe line (38) connecting the second chamber (20) of the booster (300) to the partial vacuum chamber (26) of the booster (300). 7. The boost type fluid brake system according to claim 6, wherein the solenoid valve (500 ') is of a proportional type. 8. A boost type fluid brake system according to claim 6, wherein the solenoid valve (500 ') is a three-way two-position type. 9. A boost fluid brake system according to claim 7 or 8, wherein the solenoid valve (500 ') is in the first position and the partial vacuum of the second chamber (20) of the controller (100) and the booster (300). The communication with the chamber (26) is allowed, this communication is blocked in the second position, and the control device (10
The boost type fluid brake device characterized in that the second chamber (20) of (0) is connected to the high pressure source (A).